Reaading dimensions with out side micrometers

 Reading dimensions with outside micrometers

. The required range of a micrometer

. read micrometer measurements

Ranges of outside micrometer

Outside micrometers are available in ranges of 0 to25mm, 25 to 50mm, 50 to 75mm, 75 to 100mm, 100 to 125mm and 125 to 150mm.

For all ranges of micrometers, the graduations marked on the barrel is only0-25mm.

Reading micrometers

How to read measurement with an outside micrometers

First note the minimum range of the  outside micrometers. While measuring with a 50 to 75mm micrometers, note it as 50mm.

Then read the barrel graduation. Read the value of the visible lines on the left of the thimble edge

13.00mm+00.50mm=13.50mm

Next  read the thimble graduations.

Read the thimble graduations in the with the barrel datum line, 13th div.

Multiply this value with 0.01mm(least count). 13*0.01mm=0.13mm

Add

Minimum range      50.00mm

Barrel reading         13.50mm

Thimble reading     00.13mm

Total                           63.63mm

The micrometers reading is 63.63mm